An open label study comparing the pharmacokinetic characteristics of once a day dosing vs twice a day dosing of Sandimmune in stable renal allograft recipients, then pharmacokinetics after conversion to Neoral twice a day. Patients will be followed for 8 weeks to compare the different effects of the two dosing regiments. They will have four PK profiles to compare these characteristics in the different dosing profiles and safety will be monitored by frequent blood chemistries and blood pressure monitoring.